import java.util.LinkedList;
import java.util.Queue;

public class BinaryTree {
    int data;
    BinaryTree lchild, rchild;


    public static void main(String[] args) {

        int[] a = new int[10];
        for (int i = 0; i < 10; i++) a[i] = i;
        BinaryTree t = new BinaryTree();

        t = t.initTree(t, a);
        t.preOrder(t);
        System.out.println("");
        t.inOrder(t);
        System.out.println("");
        t.postOrder(t);

    }

    //建立一完全二叉树
    public BinaryTree initTree(BinaryTree t, int[] datas) {

        //如果数组为空，返回空值
        if (datas.length <= 0) return null;

        //借助队列实现非递归赋值
        Queue<BinaryTree> trees = new LinkedList<BinaryTree>();
        //根节点入队
        t.data = datas[0];
        trees.add(t);
        int index = 0;
        while (index < datas.length - 2) {

            BinaryTree tParrent = trees.poll();

            if (++index <= datas.length) {
                BinaryTree leftTree = new BinaryTree();
                leftTree.data = datas[index];
                tParrent.lchild = leftTree;
                trees.offer(leftTree);
            } else break;
            if (++index <= datas.length) {
                BinaryTree rightTree = new BinaryTree();
                rightTree.data = datas[index];
                tParrent.rchild = rightTree;
                trees.offer(rightTree);
            } else break;
        }
        return t;
    }

    public void preOrder(BinaryTree t) {
        if (t != null) {
            System.out.print(t.data);

            preOrder(t.lchild);
            preOrder(t.rchild);
        }
    }

    public void inOrder(BinaryTree t) {
        if (t != null) {

            inOrder(t.lchild);
            System.out.print(t.data);

            inOrder(t.rchild);
        }
    }

    public void postOrder(BinaryTree t) {
        if (t != null) {

            postOrder(t.lchild);

            postOrder(t.rchild);
            System.out.print(t.data);
        }
    }


}
